EUNIS habitat classification 2012 amended 2019 > A - Marine habitats > A3 - Infralittoral rock and other hard substrata > A3.1 - Atlantic and Mediterranean high energy infralittoral rock > A3.11 - Kelp with cushion fauna and/or foliose red seaweeds > A3.112 - Alaria esculenta forest with dense anemones and crustose sponges on extremely exposed infralittoral bedrock

Alaria esculenta forest with dense anemones and crustose sponges on extremely exposed infralittoral bedrock

English name: Alaria esculenta forest with dense anemones and crustose sponges on extremely exposed infralittoral bedrock

Description (English)

This biotope has only been recorded from Rockall, where Alaria esculenta appears to replace Laminaria hyperborea as the dominant kelp forest species on the extremely wave-exposed steep and vertical rock, a zone that extends from 14 m down to 35 m. Beneath the A. esculenta canopy, the rock surface is covered by a dense turf of anthozoans such as Sagartia elegans, Phellia gausapata and Corynactis viridis, encrusting sponges and coralline algae. The gastropod Margarites helicinus can be found grazing on the kelp fronds, whereas the crab Cancer pagurus can be found among the kelp stipes. The bryozoan Tubularia indivisa also occur, but it does not form such a dense turf as in more shallow waters, while the ascidian Botryllus leachi is found encrusting the large brown seaweeds. Cryptopleura ramosa is the dominant red seaweed on horizontal surfaces. The kelp Laminaria digitata is reported to occur mixed with A. esculenta on the nearby Helen's reef.
Situation: Above the zone with A3.112 (about 5 m to 13 m) A. esculenta still dominates, but it resembles more closely the typical sublittoral fringe A. esculenta biotope (unit A3.1111), though it has a very dense turf of small hydroids and few foliose algae. Towards the lower part of this A. esculenta forest (30 m to 35 m), the density of A. esculenta is reduced and the rock surface is characterised by a dense turf of red algae (unit A3.116).

Source: EUNIS habitat classification

Quick facts

EUNIS habitat type code A3.112
Bern Convention Included in a Resolution 4 habitat type at a higher level (A3)

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Species mentioned in habitat description

Algae Alaria esculenta
Algae Cryptopleura ramosa
Algae Laminaria digitata
Algae Laminaria hyperborea
Invertebrates Botryllus leachi
Invertebrates Cancer pagurus
Invertebrates Corynactis viridis
Invertebrates Margarites helicinus
Invertebrates Phellia gausapata
Invertebrates Sagartia elegans
Invertebrates Tubularia indivisa
Species scientific name English common name Species group
Alaria esculenta Algae
Cryptopleura ramosa Algae
Laminaria digitata Algae
Laminaria hyperborea Algae
Botryllus leachi Invertebrates
Cancer pagurus Invertebrates
Corynactis viridis Invertebrates
Margarites helicinus Invertebrates
Phellia gausapata Invertebrates
Sagartia elegans Invertebrates
Tubularia indivisa Invertebrates

Other classifications

Classification Code Habitat type name Relationship type
Marine Habitat Classification Britain/Ireland 0405 IR.HIR.KFaR.AlaAnCrSp <I>Alaria esculenta</I> forest with dense anemones and crustose sponges on extremely exposed infralittoral bedrock source
CORINE Land Cover 5.2.3. Sea and ocean n/a
For relation to plant communities (syntaxa), see Vegetation types

History

Classification Code Habitat type name Relationship type
EUNIS Habitat Classification 200410 A3.112 Alaria esculenta forest with dense anemones and crustose sponges on extremely exposed infralittoral bedrock same
EUNIS Habitat Classification 200308 A3.112 Alaria esculenta forest with dense anemones and crustose sponges on extremely exposed infralittoral bedrock same
EUNIS Habitat Classification 200202 A3.112 Alaria esculenta forest with dense anemones and sponge crusts on extremely exposed infralittoral bedrock same
EUNIS Habitat Classification 199910 A3.112 Alaria esculenta forest with dense anemones and sponge crusts on extremely exposed infralittoral bedrock same
MNCR BioMar 97.06 (Britain & Ireland) EIR.KFaR.AlaAnSC Alaria esculenta forest with dense anemones and sponge crusts on extremely exposed infralittoral bedrock same
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